<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>filter过滤数组</title>
</head>
<body>
  <script>
  const arr=[100,200,10,20,30,4,56]
  const newArr=arr.filter(function(item,index){
  console.log(item)
  // console.log(index)
  return item>20
  })
  console.log(newArr)
  </script>
</body>
</html>